There are many instances in which it may be desirable to deliver a drug to a patient. The term “drug” as used herein refers to any functional agent that can be delivered to a human or animal subject, including hormones, stem cells, gene therapies, chemicals, compounds, small and large molecules, dyes, antibodies, viruses, therapeutic agents, etc.
Delivery of the drug can be done in a systemic manner, or can be targeted to a particular location or a particular distribution pattern. Targeted drug delivery can be challenging, however, as there are many instances in which the intended delivery target is not accessible, or not accessible in a minimally-invasive manner.
The natural physiology of the patient can also present drug delivery challenges. For example, achieving a desired or optimal drug distribution via intrathecal delivery can be difficult, at least in part due to the natural flow of CSF within the patient, which tends to be oscillatory and pulsatile with little net flow. Traditional techniques which involve delivering a large quantity of a drug to the intrathecal space and relying on natural diffusion to distribute the drug are inefficient and may be harmful to the patient.
There is a continual need for improved drug delivery systems and methods.